Require device:time_zone_monitor capability on content_utility

This requirement is missing from content_utility's manifest.

BUG=None
TBR=ben@chromium.org

Review-Url: https://codereview.chromium.org/2621203002
Cr-Commit-Position: refs/heads/master@{#442753}

content/public/app/mojo/content_utility_manifest.json

@@ -13,7 +13,10 @@
         ]
       },
       "requires": {
-        "device": [ "device:power_monitor" ]
+        "device": [
+          "device:power_monitor",
+          "device:time_zone_monitor"
+        ]
       }
     }
   }